Do aging males make poorer quality sperm? Older mothers face a well-established risk of producing eggs with chromosome abnormalities, but it is less clear how age affects meiosis in males.

In the February issue of GENETICS, Vrooman et al. investigated chromosome dynamics during spermatogenesis in mice of different ages. They found that meiotic errors increased with mouse age, but this did not seem to result in more aneuploidy at metaphase II. Their results suggest that although meiosis was more error-prone in the older males, aneuploid germ cells were effectively eliminated by cell cycle checkpoint mechanisms.